--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/servlib/prophet/Alarm.h	Thu Apr 21 14:57:45 2011 +0100
@@ -0,0 +1,117 @@
+/*
+ *    Copyright 2007 Baylor University
+ * 
+ *    Licensed under the Apache License, Version 2.0 (the "License");
+ *    you may not use this file except in compliance with the License.
+ *    You may obtain a copy of the License at
+ * 
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ *    Unless required by applicable law or agreed to in writing, software
+ *    distributed under the License is distributed on an "AS IS" BASIS,
+ *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *    See the License for the specific language governing permissions and
+ *    limitations under the License.
+ */
+
+#ifndef _PROPHET_ALARM_H_
+#define _PROPHET_ALARM_H_
+
+#include <sys/time.h>
+#include <sys/types.h>
+#include <vector>
+#include <string>
+
+namespace prophet
+{
+
+/**
+ * Alarm expiration handler
+ */
+class ExpirationHandler
+{
+public:
+    /**
+     * Constructor
+     */
+    ExpirationHandler(const std::string& name = "")
+        : name_(name) {}
+
+    /**
+     * Destructor
+     */
+    virtual ~ExpirationHandler() {}
+
+    /**
+     * Method to invoke when associated alarm expires
+     */
+    virtual void handle_timeout() = 0;
+
+    /**
+     * Accessor
+     */
+    const char* name() { return name_.c_str(); }
+
+    /**
+     * Mutator
+     */
+    void set_name(const char* name) { name_.assign(name); }
+
+protected:
+    std::string name_;
+
+}; // class ExpirationHandler
+
+/**
+ * Alarm registration
+ */
+class Alarm
+{
+public:
+    /**
+     * Constructor.
+     */
+    Alarm(ExpirationHandler* handler)
+        : handler_(handler) {}
+    
+    /**
+     * Destructor.
+     */
+    virtual ~Alarm() {}
+
+    /**
+     * How many milliseconds in the future to schedule this alarm
+     */
+    virtual void schedule(u_int milliseconds) = 0;
+
+    /**
+     * Milliseconds remaining until alarm expires
+     */
+    virtual u_int time_remaining() const = 0;
+
+    /**
+     * Disable the alarm; do not execute the handler. It is expected
+     * that the host's timer implementation will cleanup a cancelled
+     * Alarm's memory ...
+     */
+    virtual void cancel() = 0;
+
+    /**
+     * Invoke timeout handler. It is expected that a successfully
+     * executed ExpirationHandler will clean up Alarm's memory
+     */
+    virtual void timeout() { handler_->handle_timeout(); }
+
+    ///@{ Accessors
+    virtual bool pending() const = 0;
+    virtual bool cancelled() const = 0;
+    ///@}
+
+protected: 
+    ExpirationHandler* const handler_; ///< action to perform when
+                                       ///  alarm expires
+}; // class Alarm
+
+}; // namespace prophet
+
+#endif // _PROPHET_ALARM_H_